bit field padding in C

Question

Continuing my experiments in C, I wanted to see how bit fields are placed in memory. I\'m working on Intel 64 bit machine. Here is my piece of code:

#include <         


        

Answer 1

From the ISO C standard:

An implementation may allocate any addressable storage unit large enough to hold a bit- field. (and later) There may be unnamed padding at the end of a structure or union.

So there's no requirement to always choose the smallest possible chunk of memory for the struct. And since 32-bit words are probably the native size for your compiler, that's what it chooses.